jarensoloff.weebly.comjarensoloff.weebly.com/.../1/47114057/lab_report-final.docx · Web viewOne such study that utilized the triangle test was published in the Journal of Sensory

Sensory Evaluation

Jaren SoloffNutrition 205

March 13, 2013

1

Abstract

Sensory evaluation of foods and beverages can be done by using various methods which are specific to the questions being asked. Several sensory evaluations were performed in the foods and nutrition lab at San Diego State University with a panel of food science students whom were inexperienced in sensory testing. This experiment was conducted in order to evaluate the associations of beverage colors with their perceived characteristics, apply descriptive terms to food samples, differentiate between apple juices with various citric acid concentrations using triangle and paired comparison tests, score and rank apple juices according to sourness, and also used duo-trio tests to differentiate between Nabisco Nilla Wafers and store brand Vanilla Wafers. Our nutrition 205 labs found that lighter yellow beverages are perceived as both sour and natural, while darker green beverages are perceived as artificial and sweet. Panelists were able to see how an untrained tasting panel described the different characteristics of goldfish crackers, raisins, almonds, and marshmallows. We also found that the panel was able to successfully use the triangle and paired comparison to differentiate between apple juices with different acidic concentrations. We discovered that the panel could also use the duo-trio to pair the Nabisco Nilla Wafer with the standard and differentiate from the Store Brand Vanilla Wafer. In addition, the nutrition 205 student panel was also able to successfully rank apple juices with citric acid concentrations ranging from 0-10% in order from least sour to most sour. Lastly, the panelist were able to measure the panelists’ perceptions of sourness when given a reference point on a scale by using a scoring test. The overall goal of the sensory test was achieved because students learned about the importance of sensory evaluation in a broader scope and the importance of accuracy when performing these tests.

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Introduction

Selection of food and beverages has come a very long way since the days where

the only options available options consisted of meat, milk, grains, fruits and vegetables.

Now the selections are endless, food companies offer thousands of prepared and

prepackaged foods and can make it more difficult for the consumer to discern what

products will be beneficial for a nutritious diet. We may choose a food based on the

varying colors we see, how it is packaged or how it is presented to us by the media in

advertisements. Food is no longer chosen based on nutritional value, but is determined

by a variety of very personal psychological factors such as how foods look and taste,

culture, religion, health, social needs and budgetary constraints. Food companies

recognize these factors and compete fiercely to develop products that will hone in on

these aspects and appeal to a greater number of consumers. When people chose a food

they evaluate it consciously or unconsciously, and evaluate it primarily by the way it

looks, smells, feels, tastes or even sounds, and thus food companies realize the advantage

of using studies that are conducted with people instead of machines or lab equipment to

better perceive how a new product will be perceived in the market. Although results are

subjective due to the wide variability in food selection factors such as those stated earlier,

the panelist still play a vital role in helping determine the effectiveness of marketing a

product to a larger population. The desired objectives of conducting sensory evaluations

is to eliminate personal biases and make a definitive evaluation of a product based on its

appearance, flavor, texture, and odor and communicate it to the prompters for data

analysis. Overall, sensory evaluation plays a huge role in the food industry and in our

consumer markets; however there are many aspects of sensory evaluation which should

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be detailed further.

There are two distinctive types of sensory evaluations, affective tests and

analytical or effective tests (Brown, 2011). Affective tests aim to detect individual

preferences and thus allow for a wide range of panelists. One example of an affective test

that is commonly used is the hedonic test which can be administered in a variety of ways.

For example, patients in a hospital may be asked to rate their level of discomfort using a

scale of faces ranging from happy to sad, while another hedonic test may have a scale of

highly dislike to highly like, but both give a quantitative way of scoring the participant

based on their individual preference.

Distrinct from affective tests are analytical tests. Analytical tests are usually done

while using trained tasters as panelists and consist of two subcategories. The first

subcategory is discriminative testing which includes sensitivity tests for flavor detection

by using different concentrations and dilutions. A discriminative test was utilized in our

laboratory to test the association of colored beverages according to sweetness, sourness

and appearance. Similarly, a discriminative test published in Journal of Food Quality

(2005) sought to see the association between color and thirst quenching ability, sweetness

and acceptability in sports drinks. The study used different beverages with varying

sweetness and other factors to determine if panelists could identify the different

concentrations and dilutions. The second subcategory of analytical tests are difference

tests which include triangle, paired comparison, duo-trio, ranking, and ordinal which all

aim to see if the panelists can detect a difference when in comparison with other

products, they will be further discussed below.

The first example of a difference test is the triangle test. A triangle test aims to

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detect differences between three samples. In a triangle test, two of the samples are

identical and the third is different and panelists are asked to identify which the odd

sample is out of the three. Triangle tests are used for a variety of reasons in the food

industry to see if consumers can identify a companies certain product or to see if their

product matches the same degree of quality of flavor profile. One such study that utilized

the triangle test was published in the Journal of Sensory Studies (2007) used a triangle

test to have trained panelists discriminate bitterness in beer to help develop the most

desirable flavor profile and thus help create a better sale.

The Duo-Trio test is another difference test. The duo-trio differs from the

triangle because panelist are given a “standard” product and asked to evaluate which

other sample is most similar to the standard. This test is useful because it is quick and

easy to set up, however its disadvantage is that it requires a large sample size.

The paired comparison test is a difference test where two randomly coded

samples are presented simultaneously and panelists are asked to record which sample has

more of a particular characteristic. The chance of selecting the desired sample is 50%, or

one out of two. Preference tests were performed in a study in the Journal of Sensory

Studies (2008) used paired preference tests and a hedonic test to test characteristic of

potato chips, chocolate chip cookies and orange juice and compared the results to see

which reduced the risk for consumers to give a “false preference.” The different stimuli

were presented in pairs and panelists were asked to rate which sample in order of

preference. Paired comparison tests are useful in helping companies determine if a

product should include more of a given characteristic.

The ranking test is also a difference test in which panelists are given two or

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more samples and asked to asked to rank them based on the presence of a particular

characteristic, with the one with the greatest intensity being number 1 and the least

intensity being number 5. For example, a study from the Journal of Agricultural and Food

Chemistry (2007) was conducted to try and identify the odor threshold of strawberries.

The study had trained sensory panelists rank 12 potent odorants added to a juice mixture

and had panelists rank which juice had the strongest strawberry odor. Panelists ranked the

juices in order of most too least potent. They were also instructed to place the samples on

the appropriate sample number which was labeled on a sheet and to describe the sample

after they had tasted it. The ranking test are useful for identifying the desired amount of a

particular characteristic in a product based on panelist preference.

Descriptive tests aim to evaluate the flavor, texture profile of a certain food or

beverage. A study conducted in the Journal of Food Science (2002) to evaluate the terms

used to describe cracker-coated peanuts ad roasted peanuts used descriptive tests to

collect data. In the study, panelists were trained and given a list of 10 descriptive terms to

describe the samples and identify them, the study sought to determine the overall

acceptance and flavor ratings of the cracker-coated peanuts and roasted peanuts.

Descriptive tests are useful in determining consumer perceptions of a product and have a

wide variety of applications in the food industry.

While the procedures of both affective and effective tests differ slightly, they

share a common goal of providing a thorough evaluation of a certain product. Each test

has varying limitations and thus, to receive statistically significant data, a variety of tests

are used. The combination of these sensory tests allows for the testing, analyzing and

perception of products to be done before it enters the market, and thus prove to be a vital

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part of the food industry.

Methods

PANELISTS:

A study was conducted on sensory evaluations of foods and beverages at San

Diego University. There were 43 untrained students enrolled in the Foods and Nutrition

major selected as panelists. The students were from two separate lab sections of the

Nutrition 205 class. There were 23 students in the 9:00am lab, and 20 in the 1:00pm,.

Each lab section participated separately in the study and the data was compiled after

everyone had completed the evaluations. Form data collected by a demographic

questionnaire, their ages ranged from 19 years to over 40, with the majority (51%) of

participants ages 20-22. The majority of the panelists were female (86%) and (13.9%)

were male. The majority of participants (65%) lived with two or more roommates where

as 26% had one roommate and 8% lived alone. Regarding marital status, 81.4% were

single and 18.6 were divorced. The majority of the class were non smokers (97.6%) and

(2.3%) were smokers. The class consisted of 90.7% undergraduates and 9.3% graduate

students, however 100% were Foods and Nutrition majors. Of these 43 panelists, only 6

students had allergies which included gluten, lactase, nuts and salmon. There were two

administrators of the survey which included the 2 instructors and the lab technician for

the Nutrition 205 lab.

ENVIRONMENT:

The seven surveys took place in the Food and Nutritional science laboratories.

The room consisted of rows of desks and various stove tops, washing stations and

refridgerators. The walls were white and the lights were bright. There were several

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students who had colds that were coughing and had to step out of the room at several

points during the food evaluations and proved to be a distraction for other students. The

environment was quiet but there were a few students who were chatting and provided

distractions. In addition, panelists were not separated and thus when samples were

distributed students curiously looked around in anticipation.

ASSOCIATION OF COLOR IN BEVERAGES WITH SOURNESS, SWEETNESS,

AND APPERENCE:

For the association of color in beverages test the lab technician first filled 5 clear

containers with unknown liquids and placed them on the desk in front of the room so that

every panelist could see them clearly. Particpants received a handout for the association

test (Appendix A). The lab technician introduced each container and arranged them from

left to right in order from lightest to darkest in color. She introduced the liquids by

describing their color as light yellow, dark yellow, chartreuse, dark chartreuse, and

emerald green. The actual contents of the containers were known by the lab instructors

and were Mountain Dairy Lemonade, Xtremo Citrico Vibrante Gatorade, Lemon lime

Gatorade plus Green Squall Powerade, Green Squall Powerade, and Watermelon

Gatorade in order from lightest to darkest respectively. The students were first asked to

record by vision alone which liquid they thought was the sweetest, the sourest, the most

artificial most natural, which they would prefer the most, and which they disliked the

most. Students were also asked what temperature they would drink the beverage at with

the choices being: hot, warm, tepid or cold. The students recorded answers on handout

sheets which they received from the instructor. The instructor surveyed the answers by

having the panelists raise their hands after she read off the selection which matched their

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answers. The panelists were instructed to keep their hands raised high until all were

counted. Recording the data in this manner had to be repeated twice because of

individuals not raising their hand high enough, resulting in inaccurate counts. The student

assistant then entered all of the counts into an excel spread sheet on his computer.

EVALUATION OF FOOD PRODUCTS USING DESCRIPTIVE TERMS:

For the evaluation of food products using descriptive terms, the instructor told all

of the participants that during their evaluations they were to remain silent, seated, not

look around or do anything of a distractive nature which included making faces in

response to the taste of any sample. The instructor gave each panelist a handout

(Appendix A) which listed commonly used descriptive terms from previous experiments

used to describe the samples. Before beginning the testing the lab technician walked

around the room and distributed 1 disposable cup filled with deionized water to each of

the panelists and instructed students to cleanse their palates between each sample with the

water. On trays, the lab technician and instructor distributed 4 (2OZ ) paper cups to each

panelist. The panelist were instructed not to sample their product until all panelist had

received a sample. Each cup contained 2 of the following: Goldfish Snack Crackers,

Raisins, Raw Almonds, and Miniature Marshmallows. Panelists were instructed to

evaluate the appearance, aroma, flavor, texture, and consistency of each by using the

assigned words. The panelists recorded their descriptive terms on a paper distributed by

the instructor. The instructor surveyed the answers by having the panelists raise their

hands after she read off the selection which matched their answers. The panelists were

instructed to keep their hands raised high until all were counted; this had to be repeated

numerous times because the counts did not add up to the total number of panelists. The

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teachers assistant entered all of the counts into an excel spread sheet on his computer.

DUO TRIO:

For the Duo Trio test, the instructor told all of the participants that during their

evaluations they were to remain silent, seated, not look around or do anything of a

distractive nature which included making faces in response to the taste of any sample.

The lab instructor distributed a handout (Appendix A) which stated the purpose of the

Duo Trio test was to determine which cookie sample differs from the standard presented

first and included the sample numbers and scoring or rating test scale. Before distributing

the samples, the lab technician distributed 1 disposable cup filled with deionized water to

each of the panelists. Panelists were instructed to cleanse their palates between each

sample with the water. On a tray, the instructor and lab technician distributed three

cookies to each panelist and told them to wait for everyone else to receive them before

sampling. The panelists were unaware of the differences between the three cookies

because they were labeled with randomized sample numbers. Two of the cookies were

the same Nabisco Nilla Wafers and the other was a store brand First (Smart and Final)

Vanilla Wafer. Panelists were instructed to eat them and then record which was different

and which two were the same. They were also asked to describe which sample differed

from the standard and what the major difference between the two was. The data was

collected by having the panelists raise their hands after she read off the selection which

matched their answers. The panelists were instructed to keep their hands raised high until

all were counted; this had to be repeated numerous times because the counts did not add

up to the total number of panelists. The teachers assistant entered all of the counts into an

excel spread sheet on his computer.

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PAIRED COMPARISON:

For the paired comparison test, the instructor told all of the participants that

during their evaluations they were to remain silent, seated, not look around or do

anything of a distractive nature which included making faces in response to the taste of

any sample. The lab instructor distributed a handout (Appendix A) for the paired

comparison test and panelists were instructed to record which sample was the most sour.

The lab technician offered refills to panelists who had consumed all of their deionized

water, and panelists were again instructed to cleanse their palates between each sample

with the water. Panelists were instructed to use their handouts with the sample numbers

to place the samples on so they would not confuse the samples. The instructors then

asked the panelists from the front of each row went up to the desk in front of the room

and filled two samples from two separate beakers for themselves and two for each

panelist in their row. The lab instructor demonstrated the proper amount of liquid ( a

scant) that was to be poured into each sample cup. They poured just enough to cover the

bottom of 2OZ paper cups with the respective liquid from the labeled beakers and placed

them on lunch trays. They waited for everyone to finish before they preceded to handout

enough for each person in their row while informing them which random number applied

to which sample. Only the instructors knew the respective samples citric acid

concentration. The panelists were given two paper cups with one containing 0% citric

acid concentration apple juice and the other containing 1% citric acid concentration apple

juice mixture. The instructor surveyed the answers by having the panelists raise their



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TRIANGLE TEST:

For the triangle test, the instructor told all of the participants that during their



The lab technician distributed a handout (Appendix A) for the triangle test and panelists

were instructed to identify taste and identify which two were the same and which was

different and then record it on their handout. The lab technician offered refills for the

deionized water cups. Panelists were instructed to cleanse their palates between each

sample with the water. Panelists were instructed to use their handouts with the sample

numbers to place the samples on so they would not confuse the samples. The panelists

from the front of each row went up to the desk in front of the room and filled three

samples from three beakers for themselves and three for each panelist in their row. They

poured just enough to cover the bottom of 2OZ paper cups with the respective liquid from

the labeled beakers and placed them on lunch trays. They waited for everyone to finish

before they distributed enough for each person in their row while informing them which

random number applied to which sample. Only the instructors knew the respective

sample contents. The panelists received two samples of 0% citric acid concentration

apple juice and one sample of 1% citric acid concentration apple juice mixture. The

instructor surveyed the answers by having the panelists raise their hands after she read off

the selection which matched their answers. The panelists were instructed to keep their

hands raised high until all were counted; this had to be repeated numerous times because

12

the counts did not add up to the total number of panelists. The teachers assistant entered

all of the counts into an excel spread sheet on his computer.

RANKING TEST:

For the ranking test, the instructor told all of the participants that during their



Instead of a handout, the lab instructor instructed students to record their selection in their

notebooks. The lab technician offered refills for those who were out of deionized water.

Panelists were instructed to cleanse their palates between each sample with the water.

Panelists were instructed to use their handouts with the sample numbers to place the

samples on so they would not confuse the samples. The panelists from the front of each

row went up to the desk in front of the room and filled five samples from five separate

beakers for themselves and five for each panelist in their row. They poured just enough

to cover the bottom of 2OZ paper cups with the respective liquid from the labeled beakers

and placed them on lunch trays. They waited for everyone to finish before they preceded

to handout enough for each person in their row while informing them which random

number applied to which sample. The contents of the samples were only known to the

instructor. The panelists were given five samples that contained 0%, 1%, 2.5%, 5%, and

10% citric acid concentration apple juice mixtures. They were then asked to rank the

samples tastes from sourest to least sour; 1 being sourest and 5 being least sour and were

also asked to rank them by preference with 1 being most preferred and 5 being least

preferred. The instructor surveyed the answers by having the panelists raise their hands

after she read off the selection which matched their answers. The panelists were

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SCORING:

For the scoring test, the instructor told all of the participants that during their



The lab technician instructed panelists to record their evaluation on a previous handout

(Appendix A) for the scoring test. The lab technician offered refills for students who had

consumed all of their deionized water. They were instructed to cleanse their palates

between each sample with the water. Panelists were instructed to use their handouts with

the sample numbers to place the samples on so they would not confuse the samples. The

panelists from the front of each row went up to the desk in front of the room and filled

three samples from three separate beakers for themselves and three for each panelist in

their row. They poured just enough to cover the bottom of 2OZ paper cups with the

respective liquid from the labeled beakers and placed them on lunch trays. They waited

for everyone to finish before they preceded to handout enough for each person in their

row while informing them which random number applied to which sample. The contents

were only known by the instructors. The panelists were then given three samples

containing 1%, 2.5%, and 5% citric acid concentration apple juice mixtures. Panelists

were informed that the mixture of 2.5% was ranked 4 on a scale of 1-7, with 1 being most

sour and 7 being least sour. The panelists were instructed to drink all three and record

where on the scale the other two samples would fell in comparison with the number 4

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ranked sample. The instructor surveyed the answers by having the panelists raise their





Results

ASSOCIATION OF COLOR PERCEPTION IN BEVERAGES IN TERMS OF

SOURNESS, SWEETNESS AND APPEARANCE

The beverage perceived to be the sweetest by the panelists was the Dark

Chartruse which received 30% of the panelists votes. The second beverage that was the

perceived sweetest was the Emerald Chartruse with 28% of the votes, following close

behind was the Dark Chartruse with 20% and finally the Light Chartruse with 12% of the

votes and Chartruse with 9% of the votes (Table 1.1).

Light Yellow Dark Yellow Chartruse Dark Chartruse

Emerald0%5%

10%15%20%25%30%35%

12%

30%

9%

21%

28%

Table 1.1 The Perception of Sweetness in Colored Beverages

Beverage Color

Per

cen

t of

Stu

edn

ts

15

In terms of sourness, the Light Yellow beverage was perceived to be the sourest by 58%

of the panelists, followed by Dark Yellow with 19%, Chartuse with 7%, Emerald with

5% and Dark Chartruse with 2% (Table 1.2).

Light Y

ellow

Dark Yell

ow

Chartru

se

Dark Char

truse

Emer

ald0%

10%20%30%40%50%60%70%

58%

19%

7%2% 5%

Table 1.2 The Perception of Sourness in Colored Beverages

Beverage Color

Per

cen

t of

Stu

den

ts

The Emerald beverage was perceived to be the most artificial by 80% of the class,

followed by the Dark Chartruse with 20% of the panelist’s votes, 4% for the Chartruse

and 2% for the Dark Yellow, none of the panelists voted for the Light Yellow beverage

(Table 1.3).

Light Yellow Dark Yellow Chartruse Dark Chartruse Emerald0

0.20.40.60.8

1

0% 2% 4%14%

80%

Table 1.3 The Perception of Artificial-ity in Colored Beverages

Beverage Color

Per

cen

t of

Stu

den

ts

16

The majority of panelists, 92% voted that the Light Yellow beverage was the most

natural, followed by the Dark Yellow with 6% of the votes, Chartruse with 2% of the

votes, dark chartruse and emerald did not receive any of the votes (Table 1.4).


Emerald0

20

40

60

80

100 92

6 2 0 0

Table 1.4 The Perception of Nat-uralness in Colored Beverages

Beverage Color

Per

cen

t of

Stu

den

ts

The Dark Yellow Colored Beverage received the majority of votes at 41%, followed by

31% for the Light Yellow, Chartruse with 11% , Dark Chartruse with 2% and Emerald

with 1% (Table 1.5).


Emerald0

1020304050

3141

112 1

Table 1.5 The Percent of Students who Prefered a Colored Bever-

ages

Beverage Color

Per

cen

t of

Stu

den

ts

17

Half (50%) of the class disliked the Emerald beverage the most, followed by the

Chartruse with 20% of the votes, dark chartruse with 11%, the light yellow with 10%,

and lastly the Dark Yellow with 8% (Table 1.6).


Emerald0

102030405060

10 8

2011

50

Table 1.6 The Percent of Students who Disliked a Colored Beverage

Beverage Color

Per

cen

t of

Stu

den

ts

The temperature panelists the panelists preferred to drink all of the beverages at was cold

with over 88% of the vote for each beverage. Tepid was the second most preferred

beverage, with 4% of votes for the Light Yellow, 6% for the Dark Yellow, 8% for the

Chartruse, 5% for the Dark Chartruse, while none for the Emerald beverage. Only 4% of

the panelists voted that they would drink the light yellow beverage warm, 0% for the

Dark Yellow, 4% for the Chartruse, 2% for the Dark Chartruse and 4% for the Emerald

beverage. Hot was the least favorable temperature with the Light Yellow beverage

receiving 2% of the votes, the Dark Yellow with 1%, none for both the Chartruse and

Dark Chartruse and 4% said they would drink the Emerald beverage hot (Table 1.7).

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Emerald0

10

20

30

40

50

60

70

80

90

10090 93

8893 92

Table 1.7 The Temperature Preference of a Colored Beverage

Cold TepidWarmHot

Beverage Color

Per

cen

t of

Stu

den

ts

When panelists were asked if they would consume each beverage 86% said they would

consume the Light Yellow beverage, 54% said they would consume the Dark yellow,

49% for the Chartruse, 42% for the Dark Chartruse, and 26% would consume the

Emerald beverage. Only 14% of participants said they would not drink the Light Yellow,

46% for the Dark Yellow, 51% for the Chartruse, 58% for the Dark Chartruse and 74%

for the Emerald beverage (Table 1.8).

Light Yel-low

Dark Yellow Chartruse Dark Chartruse

Emerald0

20

40

60

80

100 86

54 4942

2614

46 5158

74

Table 1.8 The Percent of Students who would Consume a Colored

Beverage

YesNo

Beverage Color

Per

cen

t of

Stu

den

ts

19

When asked about how many of the panelists actually drink apple juice, 82% responded

yes while 18% responded no (Table 1.9).

yes no0

102030405060708090 82

18

Table 1.9 The Percent of Students who Drink Apple Juice

Do you Drink Apple Juice?

Per

cen

t of

Stu

den

ts

EVALUATION OF FOOD PRODUCTS USING DESCRIPTIVE TERMS

The most popular term for the appearance of Goldfish was “Golden Brown”

according to 31% of the panelist, followed by “Dry” with 24% of the panelists votes, and

“Symmetrical” with 12% of the votes , while 33% of the panelists described the Goldfish

in various terms. For flavor, the most popular terms were “Salty” with 73% of votes,

“sharp” with 15%, “pasty with 2% and 10% described the flavor in other various terms.

“Crisp” received the majority of the votes in terms of texture, followed by 36% for

“Crunchy,” 9% for “flaky” and 6% for various other terms. Aroma was described as

“nothing” with 40% of the votes, “flavor” with 37%, burnt with 10% and 13% describing

the aroma in various other terms. For consistency, 58% of the panelists described it at

“brittle,’ 16% as “thin”, and 16% as “cheesy” and 10% in various other terms. “Crisp”

was the most popular term with 70% of the votes, followed by “crunch” with 17%,

“gritty” with 7% and 6% for other terms.

20

Table 1.1 Goldfis

h

Appearance

Flavo

r Texture Aroma Consistancy Mouthfeel

Golden

Brown 31% Salty 73% Crisp 49%

Nothin

g 40% Brittle 58% Crisp

Dry 24% Sharp 15% Crunchy 36% Flavory 37% Thin 16% Crunchy

Symmetrical 12% Pasty 2% Flaky 9% Burnt 10%

Chees

y 16% Gritty

Other 33% Other 10% Other 6% Other 13% 10% Other

The most popular term for the appearance of raisins was “sticky” with 52% of the

votes, “dry rough” with 17% of the votes, “assymetrical” with 9% of the votes and 22%

describing it in other terms. “Sweet” was the most popular term used to described the

flavor with 64%, followed by “fruity” with 21%, Flowery with 4% and 11% describing it

in other terms. In terms of texture, “gummy” received 38% of the votes, “chewy” with

28%, “rubbery” with 7% and 35% describing it in other terms. Fruity and sweet were the

most popular terms to describe the aroma with 33% for both, flowery with 15% and 19%

for other. Consistency was described as “chewy” with 60% of the votes, “gummy” with

23% of the votes, 9% described it as rubbery and 9% as other. Mouthfeel for the raisins

was described as “sticky” by 48% of the panelists, “slimy” with 14% and 12% with

“gritty.”

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Table 1.2

Raisin

Appearance Flavor Texture Aroma Consistancy Mouthfeel

Sticky 52% Sweet 64% Gummy 38% Fruity 33% Chewy 60% Sticky

Dry Rough 17% Fruity 21% Chewy 28% Sweet 33% Gummy 23% Slimy

Asymmetrica

l 9% Flowery 4% Rubbery 7% Flowery 15%

Rubber

y 9% Gritty

Other 22% Other 11% Other 35% Other 19% Other 9%

When describing the appearance of almonds, 36% of panelists described it as

“golden brown,” 21% described it as “dry,” and as “light brown” and 22% described it in

other terms. “Nutty” was the most popular descriptive term with 68% of the votes,

followed by “stale” with 12%, “flat” with 7% and 13% described it in other terms. When

describing texture 24% of panelists described it as “crunchy,” 19% described it as “firm”

and as “hard” and 38% described it as “other.” The most popular term for describing the

aroma was “none” with 87% of votes, “sweet” with 2% of the votes, “sour” with 2% of

votes and 9% described it as “other.” Consistency was described as “thick” and “chewy”

by 46% of the panelists, “thin” by 1% of panelists and 7% chose other terms. Mouthfeel

was voted to be “crunchy” by 60% of the panelists, “gritty” by 20% “crispy” by 7% and

other by 13% of the panelists.

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Table 1.3

Almond

AppearanceFlavor Texture Aroma Consistancy Mouthfeel

Golden Brown 36% Nutty 68%

Crunchy 24% None 87% Thick 46% Crunchy

Dry 21% Stale 12% Firm 19% Sweet 2%Chewy 46% Gritty

Light Brown 21% Flat 7% Hard 19% Sour 2% Thin 1% CrispOther 22% Other 13% Other 38% Other 9% Other 7% Other

When using descriptive terms to describe the marshmallow in terms of appearance, 87%

described it as “puffy,” 2% described it as “smooth” and “dry” while 9% described it as

other. In terms of flavor, 81% described it as “sweet”, followed by “flowery,” 5%

described it as “pasty” and 1% used other terms. For texture descriptions, 25% described

it as “velvety” 19% described it as “springy” and “moist” and 37% described it as other.

Aroma was described as “sweet” by 80% of panelists, followed by 17% describing it as

“nothing,” 2% as “flowery” and 1% as other. Consistency was described as “gummy” by

35% of the panelists, “chewy” by 22%, “buttery” by 15% and other by 18%. Mouth feel

23

was described as “smooth” by 76% of the panelists, “sticky” by 12%, “slimy” by 7% and

5% described it as other.

Table 1.4

Marshmallo

w

Appearance

Flavo

r

Textur

e Aroma Consistency Mouthfeel

Puffy 87%

Swee

t 81% Velvety 25% Sweet 80%

Gumm

y 35% Smooth

Smooth 2%

Flour

y 13% Springy 19%

Nothin

g 17% Chewy 22% Sticky

Dry 2% Pasty 5% Moist 19%

Flower

y 2% Buttery 15% Slimy

Other 9% Other 1% Other 37% Other 1% Other 18% Other

DUO TRIO TEST

The Store brand wafer was found by 82% of the panelist to be different from the

standard, which was the Nabisco Nilla Wafer. The other 17% of panelists believed that

the Nilla Wafer was in fact different from the standard (Table 1.1).

24

Different Not Different0%

50%

100% 83%

17%

Table 1.1 The Percent of Students who Believed Store Brand Wafers Differed

from Standard Wafers

Student Opinion

Per

cen

t of

Stu

den

ts

When asked what the main difference was between the samples, 49% said that the

difference was “crunchiness,” while 37% said that it was due to the “Less Vanilla,” and

14% said that it was due to “Dryness” (Table 1.2).

Dryness Crunchiness Less Vanilla0

204060

14

4937

Table 1.2 The Difference between Store Brand Wafers and Standard

Wafers

Difference in Wafers

Per

cen

t of

Stu

den

ts

PAIRED COMPARISON TEST

One Hundred (100%) of the panelists identified the beverage containing 1% citric acid

apple juice to be more sour when compared to the apple juice with 0% citric acid added.

TRIANGLE TEST

25

One-hundred (100%) of the panelists identified the sample containing 1% citric acid

concentration apple juice to be different than the other two samples containing 0% citric

acid.

RANKING TEST

The beverage with 0% citric acid concentration was voted by 92% of panelists as the

most sour. Second to that was the beverage with 5% citric acid concentration with 83%,

then then beverage with 2.5% with 72% of the votes, beverage 1% with 82% and finally

beverage 10% with 92% (Table 1.1).

10.00% 2.50% 1.00% 0.00% 5.00%0

20

40

60

80

100

Table 1.1 Colored Beverages Ranked According to Sourness

Most Sour234Least Sour

Concentration of Citric Acid in Beverage

Per

cen

t of

Stu

den

ts

The most preferred beverage was the 5% citric acid added with 88% of the panelists

votes, followed by beverage with 0% citric acid added with 67%, beverages with 10%

and 2.5% citric acid were tied with 56% and beverage with 0% was the least preferred by

80% (Table 1.2).

26

10.00% 2.50% 1.00% 0.00% 5.00%0

20

40

60

80

100

Table 1.2 Colored Beverages Ranked According to Preferance

Most Sour234Least Sour

Concentration of Citric Acid in Beverage

Per

cen

t o

f Stu

den

ts

SCORING TEST

For the beverage containing 5% citric acid , 47% of the panelists ranked it as the least

sour (1), while 44% ranked it as a 2, slight more sour and 7% ranked it as a 3 in terms of

sourness. The beverage containing 1% citric acid was ranked as a 5 in terms of sourness

by 19% of the panelists, 62% rated it as 6 and 19% rated it as a 7, being the most sour

(Table 1.1).

27

1 2 3 4 5 6 70

10203040506070

0 0 0 0

19

63

19

47 44

70 1 0 0

Table 1.1 The Rating of Sourness in Colored Beverages with dif-

ferent Citric Acid Concentrations

1% Citric Acid5% Citric Acid

Rating of Sourness

Per

cen

t of

Stu

den

ts

DISCUSSION

Color Association

The results of the color association test for beverages shows a clear

relationship between beverage color and panelists perception of sweetness, sourness,

artificiality and naturalness. The darker the beverage was in color the most sweet and

more artificial it was perceived to be. The lighter the beverage the greater the perceived

sourness and naturalness. All beverages were voted to be consumed at a cold

temperature. So it seems that lighter colored beverages are the preferred color because

they are perceived to be more natural, while the darker beverages are perceived to be

more artificial and sweetened. Similarly, the Study published in the Journal of Food

Quality which tested for color association and thirst quenching ability found that the

darker colored beverages were perceived as more thirst quenching, sweeter and more

flavor intense, however it was perceived to be less acceptable as in our sensory lab

(Clydesdale and others, 2005). Possible errors in the administration and recording of the

28

test could include how far the students were seated and their perception of color by

distance, panelists in the back may have seen the beverages differently.

Descriptive Test

For the results of the test using descriptive terms, it showed that even when

panelists are given popular words to choose from, there is still not single term that the

samples could be described by. Most of the descriptive words chosen did not even

receive more than 50% of the votes by the panelists. The results of this test show the

importance of having trained testers who have a broader vocabulary for describing the

samples, such as in the descriptive test with the roasted peanuts and cracker-coated

peanuts where panelist were required to attend extra training to participate in the

descriptive testing (Grooso and Ressureccion, 2002). Errors that occurred during the

descriptive test in the Nutrition 205 lab include the fact that there were 4 panelists who

did not participate in certain areas of the voting because of food allergies that included:

salmon, lactose, gluten and nuts, this changed the calculations because they participated

in some aspects such as aroma, but not the mouth feel.

Duo Trio , Triangle and Paired Comparison

The Duo-Trio test proved to be quite effective in identifying the standard

from the Nabisco Nilla wafer. The majority of panelists (82%) were able to differentiate

the wafers, while only 17% were not able to. Those who were not able to identify the

differences may have not recorded their evaluation of one wafer clearly enough o

differentiate the taste, or they may not have cleansed their palate enough to be able to do

so. The paired comparison and triangle test also proved to be quite effective.

In the triangle test, 100% of participants were able to identify the sample with the 1%

29

citric acid concentration from the other samples which had no citric acid added. This was

probably due to the fact that there was a significant taste different when compared to the

other samples and therefore, was easily identifiable. In the triangle test used in the study

in the Journal of Sensory Studies to detect the bitterness of beer, the reliability of the test

is further supported because panelists in the study were able to distinguish the varying

levels of bitterness in beer samples.

The paired comparison test elicited the same results as the triangle test and 100%

of the panelists were able to identify the beverage with the 1% citric acid added as the

most sour. The paired comparison test was also utilized in the study in the Journal of

Sensory Studies, and showed the strength of the paired comparison test because panelists

were able to identify the samples of chocolate chip cookies, potato chips and orange juice

that differed (Kim and others, 2008). A limitation to the paired preference test is of

course the fact that there is a 50% chance of the panelists identifying the sample.

Ranking Test

The ranking test was overall quite effective when assessing panelists ability

to rank beverages according to sourness and preference. The results may have been

improved if the test had been conducted using more samples such as in the study in the

Journal of Food and Agriculture (2007) which was testing to determine the odor of

strawberries. In that study, panelists were given a sheet of paper that was marked with the

sample number so panelists would not mix the samples up, and they were also directed to

describe each beverage after they sampled it to avoid confusion with the many samples.

This concept would have worked very well to improve the test in the 205 classroom

because students may have misplaced the beverage and not remembered what sample it

30

was, therefore ranking it improperly, or they might have forgotten what the beverage

tasted like in comparison with the other samples.

Scoring

The results of the scoring test proved to be less effective as demonstrated by

the scores that were stratified when panelists were asked to determine sourness, no

particular number had more than 50% of the panelists votes. This could be largely due to

personal preference and what one individuals preference and tolerance for sourness is.

One possible error in this test is actual tasting of the samples, panelists may not have

remembered how each one tasted in comparison, and thus there should have been more

samples available if participants needed them.

Improvements for Future Testing

Although there are some improvements to the test that are particular to a

certain test, there are some general improvements that could improve the test results and

there are also some errors that should be taken into consideration as they may have

skewed the results and thus the interpretations First off, calculations were incorrect due

to several factors, one of which included the way data was collected. One of the ways it

was collected was by having panelists raise their hands, which had to be repeated due to

inaccurate counts, panelists changing their answer or the influence of other panelists

opinions. Recording answers also proved to cause some error especially concerning test

which included more than two samples such as the ranking and scoring test because

panelists could have mixed up the samples. To improve the method of data collection,

panelists could record their answers on response sheets and also have the response sheets

include spots for panelists to place their samples on a label to avoid mixing them up.

31

Another factor affecting results was data being imputed into the computer inaccurately

mostly due to human error, this had an effect on some of the given percentages and thus

perceived outcome of the test results, due to the nature of human error there is not much

that could be done to improve this section except for more careful attention to outliers in

the data. Testing environment undoubtedly influenced the results either directly or

indirectly, for example, there were multiple disruptions in the room during the testing

period some of which included panelists reactions, using the restroom, chattering, and

some panelists who were sick. This limitation could be improved by having the panelists

be separated to limit distractions and to create a silent environment free of distractions.

Overall, the tests conducted in the Nutrition 205 classroom show how sensory tests are

effective in helping companies market and sell their particular food product. With the

opinions of real consumers companies are able to create a product using the data from

sensory tests as guidelines into what consumers preferences are.

References

Brown, A. C. (2011). Understanding food: Principles and preparation. Fourth Edition. Belmont, CA: Thomson/Wadsworth

Clydesdale. F. M., Gover, R and Fugardi, C. 2005. The Effect of Color on Thirst Quenching, Sweetness, Acceptability and Flavor Intensity in Fruit Punch Flavored Beverages. Journal of Food Quality.15:19-38.

Grosso, N.R. and Resurreccion, A.V.A. 2002. Predicting Consumer Acceptance Ratings of Cracker-coated and Roasted Peanuts from Descriptive Analysis and Hexanal Measurements. Journal of Food Science.

32

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2621.2002.tb10317.x/abstract 67: 1530–1537. Posted March 4 2006.

Kim, H. S., Lee, H. S., O’Mahony, M, and Kim, K. O. 2008. Paired Preference Tests Using Placebo Pairs and Different Response Options For Chips, Orange Juices and Cookies. Journal of Sensory Studies. 15: 417-438.

Masouka, S., Hatkopoulos, D. and O’Mahony, M. 2007. Beer Bitterness Detection: Testing Thurstonian and Sequential Sensitivity Analysis Models for Triad and Tetrad Methods. Journal of Sensory Studies.10: 295–306.

Schieberle, P. and and Hoffman, T. 2007. Evaluation of the Character Impact Odorants in Fresh Strawberry Juice by Quantitative Measurements and Sensory Studies on Model Mixtures. Journal of Agricultural and Food Chemistry. 45:227-232.

Appendix A

NUTR 205 Sensory Testing Beverage Questionnaire

Name______________________________Group Number _____ Section Number_____Do you drink Apple Juice yes NoFor each of the parameters (sweetness, sourness, naturalness, artificiality, preference and dislike) give the beverage with the most a rating of 5. Give the beverage with the least a ranking of 1. Similarly the one that is almost as sweet as the sweetest beverage receives a ranking of 4, while the next to least sweet receives a ranking of 2. The middle sample will be given a rating of 3.

33

5 4 3 2 1

For stating what temperature you would the beverage at, state whether you would drink the beverage hot, warm, tepid or cold. Fill in the cell with your choice. Complete the question “Would you drink it?” as either yes or not ONLY! Please do not use words like sometimes or maybe.

Beverage Color and Associations with Other parametersParameter 1 light

yellow2 dark yellow

3 chartreuse

4 dark chartreuse

5 emerald green

Sweetness

Sourness

Artificiality

Naturalness

Prefer

Dislike

At what temp would

you drink it?

Would you drink it?

NUTR205 Sensory Evaluation

Name______________________________Group Number _____ Section Number_____

Duo-Trio Test

Determine which cookie sample differs from the standard presented first.

Standard = 8175 Sample = 6104Sample = 1108

Most Least

34

Which sample differs from the standard? __________In your opinion what is the major difference? ____________________

Scoring or Rating Test

The reference sample, 0110, has been given an arbitrary score of 4. Rate the sour intensity of the other two samples relative to the reference.

Sample 420MSample S723

More sour 1 .________ 2. ________

3.________ 0110 4.________

5.________ 6._________

Less sour 7.________

LABORATORY REPORT EVALUATION FORMNutrition 205

Student Name

MECHANICS (20points) __

SpellingGrammatical UsageTechnical writing styleWord ChoicePunctuationText CitationList of references . . . form/format

35

Professional appearance/overall qualityAppendices

CONTENT (100 points total)

Abstract (10 points) Introduction (20 points)

Focus of reviewOrganization of reviewReference selectionExpansion beyond class material

Methods (20 points) Clarity of descriptionAccuracy of descriptionOrganization

Results (25 points) Appropriate data reductionAppropriate tables/figuresClarity of tables/figuresDescriptive/numerical data distinctionFlow/development of the text

Discussion (25 points) Comparison/contrast with the literatureCorrect interpretation of findingsIdentification of experimental error

SUBTOTAL OF FINAL EARNED POINTS ______ MINUS ANY LATE PENALTY POINTS

FINAL TOTAL POINTS EARNED – POSSIBLE 120

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37

38

39

40

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Documents

jarensoloff.weebly.comjarensoloff.weebly.com/.../1/47114057/lab_report-final.docx · Web viewOne such study that utilized the triangle test was published in the Journal of Sensory